On Mon, 15 Jan 2018 15:59:29 -0500, "Mr. Luddite"
wrote:

On 1/15/2018 1:47 PM, wrote:
On Mon, 15 Jan 2018 02:23:21 -0500, wrote:

On Sun, 14 Jan 2018 23:37:16 -0500,
wrote:

On Sun, 14 Jan 2018 22:09:37 -0500, wrote:

45 years ago I was in a bar in Chicago and they had a laser deal that
plotted the 2 channels of the sound system as a Lissajous pattern on
the back wall.
I tried to make one using an old Neon laser and mirrors on speaker
drivers about 40 years ago. It was almost working when the free used
laser I had crapped out. Now that laser diodes cost less than a stick
of gum I wanted to try again. What is the best way to steer the laser?
Piezo crystal or some kind of mirror solution


===

I'm not an expert on piezo crystal optics but I think you'll have more
fun engineering an electromechanical linkage to a mirror. It will
also be more intuitive and use readily available components.


That was my thinking before I started working on laser printers but
these days it is a pretty mature science and those parts may be as
cheap as lasers. I found out the first time down the rabbit hole, you
need a 1st surface mirror. A regular silver on glass mirror creates a
ghost image. I ended up with a dental mirror sans handle, epoxied to a
coil spring with arms going out to 2 small speaker cones 90 degrees
out. The laser I had was a neon, about 1.5" in diameter and a foot
long that needed a HV power supply to spark up. These days you can get
a diode that runs on 4.5vdc. Just about the time I got the geometry
right, my laser broke.
I came up with another laser down here but it was pressed into service
at the flower store and went with the store. That design was still a
little funky and I wanted to try something different.
I really don't believe that in the 70s they were using a crystal tho.
We did us one in a 3800 but it only deflected in one axis.
I may be missing a whole different concept in steering a laser. I
thought Richard may have dabbled in this stuff.


===

I'm assuming you'd need two mirrors - one for X axis positioning and a
second for the Y axis. There are lots of devices with fairly bright
lasers these days. Perhaps you could get one on EBAY or at a garage
sale. Of course you'd need to be happy with either red or green. I've
got some green gun sight lasers that are fairly bright, and there are
lots of laser pointers around that are allegedly bright enough to
blind aircraft pilots.



Greg: Check this out:

https://www.youtube.com/watch?v=qwawj0A8P6w

That was where the 2 lasers I scored once I moved here went. We did a
similar thing to that with mirrored flower containers on turn tables
for the Cooper Group (major Holiday In franchiser) at big 3 day
conference they had here in Ft Myers. Judy had the contract for
decorating at the conference when we had the flower store. One of the
containers was a big hex shaped thing (6 mirrors) and the other was a
disco ball sort of thing on a big cylinder. By positioning the lasers
right we had beams bouncing around the whole room. A little tobacco
smoke really got it going.
The staff decided a smoke machine would really be cool and they had
one in their disco. What they didn't know is the smoke detectors in
the disco were disabled.
Imagine a bunch of Cooper Group executives standing in the parking lot
in their underwear at 5AM (most with a hangover) waiting for the South
Trail Fire Department to tell them it was a false alarm.
They kept the lasers, they lost the smoke machine,